Contrasting effects of metal oxide dopants on the superconductivity of YBa2Cu3O7-δ ceramics

Bio-dielectric based on superconductors yttrium calcium barium copper oxide (YCaBa2Cu3O7−x ) from eggshell as calcium oxide source via sol-gel process

“…The other peak of the YCaBCO samples fired at 900 • C and 1,000 • C was at 3,450-3,500 cm −1 for ν (O-H) due to the water molecule in their structures. Furthermore, Thuy et al [21] described the FTIR results of YBCO showing a sharp peak at 565 cm −1 for Y 2 O 3 and BaCO 3 , assigned to ν (Y-O) and ν (Ba-O), respectively, while Ozabaci [22] suggested peaks of YBCO assigned at 588 cm −1 , 1,026 cm −1 , 1,085 cm −1 , and 1,216 cm −1 for ν (Y-O-Y). The strong absorption bands of YBCO located at 591 cm −1 and 701 cm −1 were assigned to the vibration of Cu-O.…”

“…Therefore, the excess firing temperature changed the phase formation of these superconductors. Furthermore, Amoudeh et al [18] and Ozabaci [22] suggested that the XRD peak patterns of YBCO had polycrystalline structure with orthorhombic phase formation. The asymmetrical orthorhombic structure affected its electrical properties such as inducing polarization at the electromagnetic frequency and increasing oxygen absorption during the critical current density.…”

Impurity effects on activation energy, structure and physical properties of Ybco superconductor

“…In order to introduce artificial pinning centers and enhance the flux pinning strength further, various approaches have been adopted previously including substitution of constitutional elements and creating defects through electron, x-ray, neutron or heavy ion irradiation [9][10][11][12]. Among these methods, chemical doping is considered to be the most effective way of enhancing Jc, because of the relative simplicity of fabrication, low-cost and flexibility.…”